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Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Practice Set 3 — Answers

Answer sheet with worked solutions for the Year 4 addition worksheet.

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Success TutoringWorksheetsAnswer sheetYear 4 · Mathematics · Addition

Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Practice Set 3 — Answers

Fill in each step of the strategy, then write the answer.

1.143 + 38 = 143 + 40 − (answer space) = (answer space)

Answer: 2, 181

  1. 143 + 40 = 183
  2. 183 − 2 = 181
2.88 − 48 = 88 − 50 + (answer space) = (answer space)

Answer: 2, 40

  1. 88 − 50 = 38
  2. I took away 2 too many, so add it back: 38 + 2 = 40
3.162 − 3 = 162 − 2 − (answer space) = (answer space)

Answer: 1, 159

  1. 162 − 2 = 160 (back to a ten)
  2. 160 − 1 = 159
4.32 + 38 = 32 + 40 − (answer space) = (answer space)

Answer: 2, 70

  1. 32 + 40 = 72
  2. 72 − 2 = 70
5.103 − 18 = 103 − 20 + (answer space) = (answer space)

Answer: 2, 85

  1. 103 − 20 = 83
  2. I took away 2 too many, so add it back: 83 + 2 = 85
6.82 − 3 = 82 − 2 − (answer space) = (answer space)

Answer: 1, 79

  1. 82 − 2 = 80 (back to a ten)
  2. 80 − 1 = 79
7.165 + 49 = 165 + 50 − (answer space) = (answer space)

Answer: 1, 214

  1. 165 + 50 = 215
  2. 215 − 1 = 214
8.63 − 49 = 63 − 50 + (answer space) = (answer space)

Answer: 1, 14

  1. 63 − 50 = 13
  2. I took away 1 too many, so add it back: 13 + 1 = 14
9.144 − 9 = 144 − 4 − (answer space) = (answer space)

Answer: 5, 135

  1. 144 − 4 = 140 (back to a ten)
  2. 140 − 5 = 135
10.198 + 18 = 198 + 20 − (answer space) = (answer space)

Answer: 2, 216

  1. 198 + 20 = 218
  2. 218 − 2 = 216
11.125 − 9 = 125 − 10 + (answer space) = (answer space)

Answer: 1, 116

  1. 125 − 10 = 115
  2. I took away 1 too many, so add it back: 115 + 1 = 116
12.161 − 2 = 161 − 1 − (answer space) = (answer space)

Answer: 1, 159

  1. 161 − 1 = 160 (back to a ten)
  2. 160 − 1 = 159
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